Regarding dating ancient prehistory...

Does the earth retain its shape throughout itself forever? I mean, isn't there some change to the geography of the earth over time?

For example, probably there was a time that the Hawaiian Islands did not exist above the water. It has been over hundreds or thousands of years that volcanic activity has gradually built the Hawaiian Islands. It is reasonably common knowledge that newish islands are forming in the Hawaiian chain while some others are receding into the ocean again. And other islands in the chain are growing, all because of volcanic action.

The point is, if the lands can change, if the geography can change, why not aspects of space-time?

When scientists start to base their equations on the idea that the physics of time has slowed way down in recent years, and that there are forms of energy that have departed from the materials of the earth, the present lack of which causes what appears to be tremendously large amounts of time, when in reality the time was relatively short, then science will really start to discover something worthwhile!